Constituents of an Extract of <i>Cryptocarya rubra</i> Housed in a Repository with Cytotoxic and Glucose Transport Inhibitory Effects

Abstract

A new alkylated chalcone (<b>1</b>), a new 1,16-hexadecanediol diester (<b>2</b>), and eight known compounds were isolated from a dichloromethane-soluble repository extract of the leaves and twigs of <i>Cryptocarya rubra</i> collected in Hawaii. The structures of the new compounds were determined by interpretation of their spectroscopic data, and the absolute configurations of the two known cryptocaryanone-type flavonoid dimers, (+)-bicaryanone A (<b>3</b>) and (+)-chalcocaryanone C (<b>4</b>), were ascertained by analysis of their electronic circular dichroism and NOESY NMR spectra. All compounds isolated were evaluated against HT-29 human colon cancer cells, and, of these, (+)-cryptocaryone (<b>5</b>) was found to be potently cytotoxic toward this cancer cell line, with an IC₅₀ value of 0.32 μM. This compound also exhibited glucose transport inhibitory activity when tested in a glucose uptake assay